CN100376551C - Semicarbazone synthesis method - Google Patents
Semicarbazone synthesis method Download PDFInfo
- Publication number
- CN100376551C CN100376551C CNB2005100614767A CN200510061476A CN100376551C CN 100376551 C CN100376551 C CN 100376551C CN B2005100614767 A CNB2005100614767 A CN B2005100614767A CN 200510061476 A CN200510061476 A CN 200510061476A CN 100376551 C CN100376551 C CN 100376551C
- Authority
- CN
- China
- Prior art keywords
- reaction
- semicarbazone
- ionic liquid
- synthetic method
- yield
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Abstract
The present invention relates to a synthetic method for semicarbazone, which comprises the following steps: 1. making hydrazine hydrate and urea react at 90 to 100 DEG C and after the reaction is finished, regulating the pH of the reaction liquid to 3 to 4 with concentrated hydrochloric acid; 2. adding aldehyde and ionic liquid to the reaction liquid for reflux reaction, and cooling and filtering the reaction liquid to obtain a target compound. The synthetic method has the advantages that 1. the ionic liquid which is easy to recover and use is not easy to volatilize, combust or explode, and has high security and favorable solubility to organic matters and inorganic matters; the reaction is carried out under a homogeneous condition, which is convenient for operation and processing, and the yield of products is high; 2. if the condensation reaction uses microwave heating, the time is obviously shortened, the yield is greatly raised, the purity is higher and the energy consumption is saved, which is favorable for industrial production; 3. if the condensation reaction is promoted with ultrasonic waves, the reaction time is shortened and the yield is enhanced.
Description
(1) technical field
The present invention relates to a kind of synthetic method of semicarbazone.
(2) background technology
The semicarbazone that aldehyde and Urea,amino-reaction generate is a kind of important fine-chemical intermediate, is mainly used in synthetic urinary tract infection antibacterials Zoofurin.
With the example that synthesizes of benzaldehyde semicarbazone, at present, its synthesis route has three kinds.Method one: hydrazine hydrate and urea reaction obtain Urea,amino-, again with concentrated hydrochloric acid separate out, separate carbamylhydrazine hydrochloride, carbamylhydrazine hydrochloride and phenyl aldehyde or the condensation of benzal propylmalonic acid diethyl ester obtain benzaldehyde semicarbazone.Condensation reaction has a large amount of bubbles to produce at refluxing stage, often causes the material overflow, adheres on the wall, brings difficulty to operation.Method two: hydrazine and front three silicon isocyanate reaction obtain the trimethyl silicane Urea,amino-, and the trimethyl silicane Urea,amino-obtains benzaldehyde semicarbazone with the phenyl aldehyde reaction.Method three: hydrazine hydrate and nitrourea reaction obtain Urea,amino-, and Urea,amino-makes benzaldehyde semicarbazone with the phenyl aldehyde reaction.In above three kinds of methods, the solubleness of the carbamylhydrazine hydrochloride that method one makes in water is bigger, has only by evaporation, spissated method to obtain, and energy consumption is big, yield is low, raw materials cost is high, and because excessive hydrazine hydrate causes serious environmental to pollute with discharging of waste liquid.The trimethyl silicane isocyanic ester dependence on import of one of method two raw material, the production cost height, production has a significant impact to large-scale industrial.Method three raw materials used nitroureas must be made by oneself, and explosive, and very unfavorable to the operation protection, the by product nitrous oxide is met air and promptly is oxidized to toxic gases such as nitrogen peroxide, causes topsoil.
Because present domestic most chemical enterprise manufacturing process are relatively backward, equipment is lower, the production of many products is still being continued to use the production technique of external 60～seventies, the equipment of 50～sixties, potential safety hazard is big, energy consumption is high, the wasting of resources is big, production cost is high, " three wastes " of production process do great damage to ecotope, even directly HUMAN HEALTH are produced harm, and chemical industry " three wastes " has become one of primary pollution source.Use green synthesis process, realize the cleaner production of Chemicals, can promote the green transformation of chemical industry, promote quick, the Sustainable development of chemical industry.
(3) summary of the invention
The object of the invention is to provide a kind of method of easy and simple to handle, the synthetic semicarbazone of green that yield is higher.
Described semicarbazone is suc as formula shown in (I), and described synthetic method comprises the steps:
(1) hydrazine hydrate and urea finish the back and transfer reaction solution pH to 3～4 with concentrated hydrochloric acid in 90～100 ℃ of reaction down;
(2) in above-mentioned reaction solution, add aldehyde and ionic liquid suc as formula (II), back flow reaction, cold filtration promptly gets target compound;
R-C＝NNHCONH
2
H (I) RCHO (II)
Its Chinese style (I) and (II) in R represent aryl or heterocyclic substituent.It is one of following that R is preferably: phenyl, p-methoxyphenyl, 3,4-dimethoxy benzene; It is one of following that R also is preferably: thiophene, pyrroles, furans, alkane, alkene, furans, thiazole, pyridine, pyrazoles, quinoline, more preferably furans or thiophene.
Reaction equation is as follows:
NH
2NH
2·H
2O+NH
2CONH
2→NH
2CONHNH
2+NH
3·H
2O
Described ionic liquid can be selected from alkyl imidazole a tetrafluoro borate, alkyl imidazole acetate, Aryimidazole a tetrafluoro borate or alkyl-imidazole hexafluorophosphate; Described alkyl carbon atoms number is C
1～C
18, described aryl carbonatoms is C
6～C
10Ionic liquid is preferably C
1～C
10The alkyl imidazole a tetrafluoro borate, most preferably be 1-butyl-3-methyl imidazolium tetrafluoroborate.
The molar ratio of hydrazine hydrate and urea is generally 1～3 in the step (1): 1, and step (2) intermediate ion liquid consumption is calculated as 50～300ml by 1mol aldehyde.
The described reaction of step (2) is preferably carried out under microwave promotes.Microwave radiation can make the reaction times shorten significantly, and yield obviously improves, and reacts more complete.
The described reaction of step (2) is also preferably carried out under ultrasonic wave promotes.The ultrasonic wave radiation is shortened the reaction times significantly, and yield improves, and energy consumption reduces.Described ultrasonic instrument can be all kinds of experiment ultrasonic cleaners.
After the present invention replaced dehydrated alcohol with ionic liquid, the condensation reaction bubble obviously reduced, and yield improves a lot, and easy to operate, and ionic liquid self can play the effect of phase-transfer catalyst.After the present invention filtered and obtains product, filtrate was used organic solvent extraction, and after steaming desolventized, ionic liquid can continue to recycle.When adopting the promoted method of ultrasonic wave, make the original reaction times shorten to 0.5h by 2h; When reacting under adopting microwave radiation, the time shortens to 3～30min from 3h, and yield also is improved.
The beneficial effect of synthetic semicarbazone Green Chemistry method of the present invention is mainly reflected in:
(1) use ionic liquid, not volatile, nonflammable explosive security is good, and organism and inorganics are all had good solubility, is reflected under the homogeneous phase condition and carries out, and is convenient to operation and handles the product yield height.Ionic liquid easily reclaims use.
(2) condensation reaction is as using microwave heating, and the time obviously shortens, and yield increases substantially, and purity is higher, has saved energy consumption, is beneficial to suitability for industrialized production.
(3) condensation reaction promotes that as using ultrasonic wave the reaction times shortens, and yield improves.
(4) embodiment
The invention will be further described below by specific embodiment, but protection scope of the present invention is not limited to this.
The benzaldehyde semicarbazone of embodiment 1 in ionic liquid is synthetic
In three mouthfuls of round-bottomed flasks of the 100mL that thermometer and prolong are housed, add urea (10g successively, 0.167mol), 50% hydrazine hydrate (9g, 0.09mol), at 100 ℃ of reaction 4h, be cooled to room temperature, transfer pH3～4 with concentrated hydrochloric acid, (9mL is 0.085mol) with 10mL 1-butyl-ion liquid mixing solutions of 3-methyl imidazolium tetrafluoroborate to drip phenyl aldehyde, the adularescent precipitation generates immediately, finish stirring at room reaction 2h, reflux 1h, cold filtration gets white crystal, 12.1g, yield 95.8%, 220～221 ℃ of fusing points.Filtrate is used dichloromethane extraction, and evaporating solvent gets 1-butyl-3-methyl imidazolium tetrafluoroborate ionic liquid, and ionic liquid reclaims and uses.
The benzaldehyde semicarbazone of embodiment 2 under ultrasonic wave promotes is synthetic
In three mouthfuls of round-bottomed flasks of the 100mL that thermometer and prolong are housed, add urea (10g successively, 0.167mol), 50% hydrazine hydrate (9g, 0.09mol), at 95 ℃ of reaction 4h, be cooled to room temperature, transfer pH3～4 with concentrated hydrochloric acid, (9mL is 0.085mol) with 10mL 1-butyl-ion liquid mixing solutions of 3-methyl imidazolium tetrafluoroborate to drip phenyl aldehyde, the adularescent precipitation generates immediately, finish, ultrasonic wave promotes reaction 0.5h down, reflux 1h, cold filtration gets white crystal, 12.2g, yield 96.4%, 219～220 ℃ of fusing points.Filtrate is used dichloromethane extraction, and evaporating solvent gets 1-butyl-3-methyl imidazolium tetrafluoroborate ionic liquid, and ionic liquid reclaims and uses.
The benzaldehyde semicarbazone of embodiment 3 under microwave radiation is synthetic
In three mouthfuls of round-bottomed flasks of the 100mL that thermometer and prolong are housed, add urea (10g successively, 0.167mol), 50% hydrazine hydrate (9g, 0.09mol), at 100 ℃ of reaction 4h, be cooled to room temperature, transfer pH3～4 with concentrated hydrochloric acid, the dropping phenyl aldehyde (9mL, 0.085mol) with 10mL 1-butyl-ion liquid mixing solutions of 3-methyl imidazolium tetrafluoroborate, the adularescent precipitation generates immediately, finish, the 125W microwave is reaction 10min down, and cold filtration gets white crystal, 12.4g, yield 98.0%, 219～222 ℃ of fusing points.Filtrate is used dichloromethane extraction, and evaporating solvent gets 1-butyl-3-methyl imidazolium tetrafluoroborate ionic liquid, and ionic liquid reclaims and uses.
The benzaldehyde semicarbazone of embodiment 4 under microwave radiation is synthetic
In three mouthfuls of round-bottomed flasks of the 100mL that thermometer and prolong are housed, add urea (10g successively, 0.167mol), 50% hydrazine hydrate (9g, 0.09mol), at 95 ℃ of reaction 3h, be cooled to room temperature, transfer pH3～4 with concentrated hydrochloric acid, the dropping phenyl aldehyde (9mL, 0.085mol) with 10mL 1-butyl-ion liquid mixing solutions of 3-methyl imidazolium tetrafluoroborate, the adularescent precipitation generates immediately, finish, the 100W microwave is reaction 30min down, and cold filtration gets white crystal, 12.3g, yield 97.2%, 220～222 ℃ of fusing points.Filtrate is used dichloromethane extraction, and evaporating solvent gets 1-butyl-3-methyl imidazolium tetrafluoroborate ionic liquid, and ionic liquid reclaims and uses.
The aubepine semicarbazone of embodiment 5 in ionic liquid is synthetic
In three mouthfuls of round-bottomed flasks of the 100mL that thermometer and prolong are housed, add urea (10g successively, 0.167mol), 50% hydrazine hydrate (9g, 0.09mol), at 95 ℃ of reaction 4h, be cooled to room temperature, transfer pH3～4 with concentrated hydrochloric acid, (10.32mL is 0.085mol) with 10mL 1-butyl-ion liquid mixing solutions of 3-methyl imidazolium tetrafluoroborate to drip aubepine, the adularescent precipitation generates immediately, finish, react 2h under the stirring at room, reflux 1h, cold filtration gets white crystal, 15.09g, yield 99.3%, 224～226 ℃ of fusing points.Filtrate is used dichloromethane extraction, obtains 1-butyl-3-methyl imidazolium tetrafluoroborate ionic liquid behind the evaporating solvent, and ionic liquid reclaims and uses.
The aubepine semicarbazone of embodiment 6 under microwave radiation is synthetic
In three mouthfuls of round-bottomed flasks of the 100mL that thermometer and prolong are housed, add urea (10g successively, 0.167mol), 50% hydrazine hydrate (9g, 0.09mol), at 95 ℃ of reaction 4h, be cooled to room temperature, transfer pH3～4 with concentrated hydrochloric acid, the dropping aubepine (10.32mL, 0.085mol) with 10mL1-butyl-ion liquid mixing solutions of 3-methyl imidazolium tetrafluoroborate, the adularescent precipitation generates immediately, finish, the 125W microwave is reaction 10min down, and cold filtration gets white crystal, 15.12g, yield 99.5%, 225～227 ℃ of fusing points.Filtrate is used dichloromethane extraction, and evaporating solvent gets 1-butyl-3-methyl imidazolium tetrafluoroborate ionic liquid, and ionic liquid reclaims and uses.
The aubepine semicarbazone of embodiment 7 under microwave radiation is synthetic
In three mouthfuls of round-bottomed flasks of the 100mL that thermometer and prolong are housed, add urea (10g successively, 0.167mol), 50% hydrazine hydrate (9g, 0.09mol), at 95 ℃ of reaction 4h, be cooled to room temperature, transfer pH3～4 with concentrated hydrochloric acid, the dropping aubepine (10.32mL, 0.085mol) with 10mL1-propyl group-ion liquid mixing solutions of 3-methyl imidazolium tetrafluoroborate, the adularescent precipitation generates immediately, finish, the 150W microwave is reaction 30min down, and cold filtration gets white crystal, 14.1g, yield 92.8%, 226～227 ℃ of fusing points.Filtrate is used dichloromethane extraction, and evaporating solvent gets 1-propyl group-3-methyl imidazolium tetrafluoroborate ionic liquid, and ionic liquid reclaims and uses.
Embodiment 8 under microwave radiation 3,4-dimethoxy benzaldehyde semicarbazone is synthetic
In three mouthfuls of round-bottomed flasks of the 100mL that thermometer and prolong are housed, add urea (10g successively, 0.167mol), 50% hydrazine hydrate (9g, 0.09mol), at 100 ℃ of reaction 4h, be cooled to room temperature, transfer pH3～4 with concentrated hydrochloric acid, add 14.1g 3,4-dimethoxy benzaldehyde and 10mL 1-butyl-ion liquid mixing solutions of 3-methyl imidazolium tetrafluoroborate has faint yellow precipitation to generate immediately, finish, the 150W microwave is reaction 20min down, and cold filtration gets light yellow crystal, 17.1g, yield 90.3%, 197～198 ℃ of fusing points.Filtrate is used dichloromethane extraction, and evaporating solvent gets 1-butyl-3-methyl imidazolium tetrafluoroborate ionic liquid, and ionic liquid reclaims and uses.
Embodiment 9 under microwave radiation 3,4-dimethoxy benzaldehyde semicarbazone is synthetic
In three mouthfuls of round-bottomed flasks of the 100mL that thermometer and prolong are housed, add urea (10g successively, 0.167mol), 50% hydrazine hydrate (9g, 0.09mol), at 100 ℃ of reaction 3h, be cooled to room temperature, transfer pH 3～4 with concentrated hydrochloric acid, add 14.1g 3,4-dimethoxy benzaldehyde and 10mL 1-propyl group-ion liquid mixing solutions of 3-methyl imidazolium tetrafluoroborate has faint yellow precipitation to generate immediately, and the 100W microwave is reaction 25min down, cold filtration gets light yellow crystal, 17.3g, yield 91.5%, 197～198 ℃ of fusing points.Filtrate is used dichloromethane extraction, and evaporating solvent gets 1-propyl group-3-methyl imidazolium tetrafluoroborate ionic liquid, and ionic liquid reclaims and uses.
The furtural semicarbazone of embodiment 10 under microwave radiation is synthetic
In three mouthfuls of round-bottomed flasks of the 100mL that thermometer and prolong are housed, add urea (10g successively, 0.167mol), 50% hydrazine hydrate (9g, 0.09mol), at 100 ℃ of reaction 3h, be cooled to room temperature, transfer pH3～4 with concentrated hydrochloric acid, the dropping furtural (7.05mL, 0.085mol) with 10mL 1-butyl-ion liquid mixing solutions of 3-methyl imidazolium tetrafluoroborate, the adularescent precipitation generates immediately, finish, the 125W microwave is reaction 3min down, and cold filtration gets the canescence crystal, 11.7g, yield 99.2%, 197～198 ℃ of fusing points.Filtrate is used dichloromethane extraction, and evaporating solvent gets 1-butyl-3-methyl imidazolium tetrafluoroborate ionic liquid, and ionic liquid reclaims and uses.
The furtural semicarbazone of embodiment 11 under ultrasonic wave promotes is synthetic
In three mouthfuls of round-bottomed flasks of the 100mL that thermometer and prolong are housed, add urea (10g successively, 0.167mol), 50% hydrazine hydrate (9g, 0.09mol), at 100 ℃ of reaction 3h, be cooled to room temperature, transfer pH3～4 with concentrated hydrochloric acid, drip furtural (7.05mL, 0.085mol)) and 10mL 1-ethyl-ion liquid mixing solutions of 3-methyl imidazolium tetrafluoroborate, the adularescent precipitation generates immediately, ultrasonic wave promotes reaction 0.5h down, reflux 1h, cold filtration get lavender crystal, 10.1g, yield 85.6%, 196～197 ℃ of fusing points.Filtrate is used dichloromethane extraction, and evaporating solvent gets 1-ethyl-3-methyl imidazolium tetrafluoroborate ionic liquid, and ionic liquid reclaims and uses.
The thiophenecarboxaldehyde semicarbazone of embodiment 12 under microwave radiation is synthetic
In three mouthfuls of round-bottomed flasks of the 100mL that thermometer and prolong are housed, add urea (5g successively, 0.084mol), 50% hydrazine hydrate (4.5g, 0.045mol), at 100 ℃ of reaction 4h, be cooled to room temperature, transfer pH3～4 with concentrated hydrochloric acid, (4.75g 0.043mol) with 10mL1-ethyl-ion liquid mixing solutions of 3-methyl imidazolium tetrafluoroborate, has faint yellow precipitation to generate immediately to drip thiophenecarboxaldehyde, finish, the 125W microwave is reaction 10min down, and cold filtration gets light yellow crystal, 5.52g, yield 77.1%, 225～227 ℃ of fusing points.Filtrate is used dichloromethane extraction, and evaporating solvent gets 1-ethyl-3-methyl imidazolium tetrafluoroborate ionic liquid, and ionic liquid reclaims and uses.
The thiophenecarboxaldehyde semicarbazone of embodiment 13 under ultrasonic wave promotes is synthetic
In three mouthfuls of round-bottomed flasks of the 100mL that thermometer and prolong are housed, add urea (5g successively, 0.084mol), 50% hydrazine hydrate (4.5g, 0.045mol), at 100 ℃ of reaction 4h, be cooled to room temperature, transfer pH3～4 with concentrated hydrochloric acid, (4.75g is 0.043mol) with 10mL1-ethyl-ion liquid mixing solutions of 3-methyl imidazolium tetrafluoroborate to drip thiophenecarboxaldehyde, there is faint yellow precipitation to generate immediately, finish, ultrasonic wave promotes reaction 0.5h down, reflux 1h, cold filtration gets light yellow crystal, 6.24g, yield 87.0%, 226～228 ℃ of fusing points.Filtrate is used dichloromethane extraction, and evaporating solvent gets 1-ethyl-3-methyl imidazolium tetrafluoroborate ionic liquid, and ionic liquid reclaims and uses.
Claims (7)
1. the synthetic method suc as formula the semicarbazone of (I) comprises the steps:
(1) hydrazine hydrate and urea finish the back and transfer reaction solution pH to 3～4 with concentrated hydrochloric acid in 90～100 ℃ of reaction down;
(2) in above-mentioned reaction solution, add aldehyde and ionic liquid suc as formula (II), back flow reaction, cold filtration promptly gets target compound;
Its Chinese style (I) and (II) in R represent aryl or heterocyclic substituent.
2. the synthetic method of semicarbazone as claimed in claim 1 is characterized in that described R is one of following: phenyl, p-methoxyphenyl, 3,4-Dimethoxyphenyl.
3. the synthetic method of semicarbazone as claimed in claim 1 is characterized in that described R is one of following: thienyl, pyrryl, furyl, thiazolyl, pyridyl, pyrazolyl, quinolyl.
4. the synthetic method of semicarbazone as claimed in claim 3 is characterized in that described R is furyl or thienyl.
5. the synthetic method of semicarbazone as claimed in claim 1 is characterized in that described ionic liquid is alkyl imidazole a tetrafluoro borate, alkyl imidazole acetate, Aryimidazole a tetrafluoro borate or alkyl-imidazole hexafluorophosphate; Described alkyl carbon atoms number is C
1～C
18, described aryl carbonatoms is C
6～C
10
6. the synthetic method of semicarbazone as claimed in claim 5 is characterized in that described ionic liquid is C
1～C
10The alkyl imidazole a tetrafluoro borate.
7. the synthetic method of semicarbazone as claimed in claim 6 is characterized in that described ionic liquid is 1-butyl-3-methyl imidazolium tetrafluoroborate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100614767A CN100376551C (en) | 2005-11-08 | 2005-11-08 | Semicarbazone synthesis method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100614767A CN100376551C (en) | 2005-11-08 | 2005-11-08 | Semicarbazone synthesis method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1762989A CN1762989A (en) | 2006-04-26 |
| CN100376551C true CN100376551C (en) | 2008-03-26 |
Family
ID=36747342
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2005100614767A Expired - Fee Related CN100376551C (en) | 2005-11-08 | 2005-11-08 | Semicarbazone synthesis method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100376551C (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102604040A (en) * | 2012-03-20 | 2012-07-25 | 哈尔滨工业大学 | Method for preparing SiCNO foamed ceramics |
| CN107098831A (en) * | 2017-04-18 | 2017-08-29 | 重庆丽澄环保科技有限公司 | A kind of preparation method of semicarbazides |
| CN108863853A (en) * | 2018-06-18 | 2018-11-23 | 苏州盖德精细材料有限公司 | The preparation method of medicine intermediate semicarbazide hydrochloride |
| CN115974728A (en) * | 2022-12-29 | 2023-04-18 | 陕西科技大学 | Synthesis of phenyl semicarbazone and identification of hexavalent chromium ions by phenyl semicarbazone |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4482738A (en) * | 1983-08-01 | 1984-11-13 | Olin Corporation | Process for preparing semicarbazide hydrochloride |
| CN1424310A (en) * | 2002-12-19 | 2003-06-18 | 中国科学院兰州化学物理研究所 | Production of twice substituted urea by amine reacted with carbon dioxide |
-
2005
- 2005-11-08 CN CNB2005100614767A patent/CN100376551C/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4482738A (en) * | 1983-08-01 | 1984-11-13 | Olin Corporation | Process for preparing semicarbazide hydrochloride |
| CN1424310A (en) * | 2002-12-19 | 2003-06-18 | 中国科学院兰州化学物理研究所 | Production of twice substituted urea by amine reacted with carbon dioxide |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1762989A (en) | 2006-04-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103524440B (en) | The preparation method of gout therapertics Lesinurad and Lesinurad intermediate | |
| CN101891649B (en) | Novel 3-cyano methyl benzoate preparing method | |
| CN100376551C (en) | Semicarbazone synthesis method | |
| CN109336808A (en) | The green new method of transition metal-catalyzed C-H carbenoid coupling reaction synthesis C-C key and N heterocyclic derivative | |
| CN102977050A (en) | Method for synthesizing 2-benzothiazolyl dimethylacetal and 2-benzothiazol formaldehyde | |
| CN105254575A (en) | Synthetic method for sulfadiazine | |
| CN109503568A (en) | A kind of preparation method of Dasatinib | |
| CN103172479A (en) | Preparation method for biaryl through palladium catalysis | |
| CN106560471A (en) | Rupatadine preparation proces | |
| CN104649966A (en) | Method for synthesizing organic intermediate 5-cyano-3-methylpyridine formic acid | |
| CN102180824B (en) | Method for preparing pyrrole derivative | |
| CN100519446C (en) | H acid waste water by natrium chloratum addition process | |
| CN104447506B (en) | The preparation method of the alkyl carbazole of 2 acetyl group 9 | |
| US20180230170A1 (en) | Protected organoboronic acids with tunable reactivity, and methods of use thereof | |
| CN105198813A (en) | Synthesizing process of 3-methyl-1 H-indazole | |
| CN105061375A (en) | Method for preparing 3-isochromanone | |
| CN105439969A (en) | Method for preparing 3,5-dioxo-1,2,4-triazole | |
| CN1986554B (en) | Preparing process of tri (4-ethoxy phenyl) bismuth | |
| CN104926847B (en) | A kind of synthesis boron aminated compounds technique and products application | |
| CN105001271B (en) | A kind of miscellaneous bimetal complexes of neodymium/sodium and its production and use | |
| Zhang et al. | Controllable synthesis of pyrazolo [3, 4-b] pyridines or substituted malononitrile derivatives through multi-component reactions in ionic liquid | |
| CN109232301A (en) | A kind of preparation method of the tetra isopropyl hydrazine of low cost and high yield | |
| CN108586340A (en) | A kind of synthetic method of 3- acyl groups hydrogenation azepines compound | |
| CN107266392A (en) | A kind of synthetic method of sulfamate | |
| CN108299303A (en) | A kind of new synthetic method of four arylpyrazoles compound |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20080326 Termination date: 20111108 |